From e36c615716cf30a7f27c00e0b8db3fb5164c8810 Mon Sep 17 00:00:00 2001
From: Johannes Gallmann <gallmann@google.com>
Date: Fri, 24 Nov 2023 10:11:46 +0100
Subject: [PATCH] Fix crash in LauncherBackAnimationController

Bug: 312949302
Flag: NONE
Test: Manual, i.e. testing quick fling back to home gesture
Change-Id: I670b2f02cab097b1d7a202a5b07fbda33d372ac8
---
 .../android/quickstep/LauncherBackAnimationController.java  | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/quickstep/src/com/android/quickstep/LauncherBackAnimationController.java b/quickstep/src/com/android/quickstep/LauncherBackAnimationController.java
index 406e9f46ae..27b3126ed8 100644
--- a/quickstep/src/com/android/quickstep/LauncherBackAnimationController.java
+++ b/quickstep/src/com/android/quickstep/LauncherBackAnimationController.java
@@ -487,10 +487,14 @@ public class LauncherBackAnimationController {
                 tryFinishBackAnimation();
             }
         });
+        if (mScrimLayer == null) {
+            // Scrim hasn't been attached yet. Let's attach it.
+            addScrimLayer();
+        }
         mScrimAlphaAnimator = new ValueAnimator().ofFloat(1, 0);
         mScrimAlphaAnimator.addUpdateListener(animation -> {
             float value = (Float) animation.getAnimatedValue();
-            if (mScrimLayer.isValid()) {
+            if (mScrimLayer != null && mScrimLayer.isValid()) {
                 mTransaction.setAlpha(mScrimLayer, value * mScrimAlpha);
                 mTransaction.apply();
             }